My "3-season" socks are acrylic crews made by Lavitt Mills. They're sold under the name "Superbilt Work Socks", model "Acrylic Amicor Crew."
They are intelligently designed, with a lace pad on top, extra heavy contoured heel pocket, and "channels" woven into the sides to allow heat to vent. Incredibly comfortable and wick moisture away efficiently.
The only time of the year I switch to wool is December through February; the rest of the time, the Superbilts keep me warm in the cold and comfortable in the heat. Absolutely the best non-wool sock I've used.
The best part? The last few pairs I bought (on sale) at $3.00/pr - though that was a couple of years ago. I stocked up!
-=[ Grant ]=-